Method of securing a semicylindrical liner in a pump bore



W. B. HOOK METHOD OF SECURING A SEMICYLINDRICAL LINER IN A PUMP BOREFab. Y, 190

3 Sheets-Sheet 1 Filed Dec. 5, 1945 BY I A": Z M Mm FITTOE/VEKS W. B.HOOK METHOD OF SECURING A SEMICYLINDRICAL LINER IN A PUMP BORE Feb, 7,H95@ 5 Sheets-Sheet 2 Filed Dec. 5, 1.945

ATTORNEY 'T' l 1:7 lt'eh 7 Il9 W. B. HOOK 294969292 METHOD OF SECURING ASEMICYLINDRICAL LINER IN A PUMP BORE Filed Dec. 5, 1945 3 Sheets-$heet 5'INVENTOR. 2 W65 6y B, #4016 BY 7 MW/M m ATTORNEYS Patented Feb. 7, 1956UNITED STATES PATENT OFFICE METHOD or SECURING sEMIoYLIN- DRICALLINER INAQQRUMP BORE The invention described herein may be manufactured and usedby or for the Government for governmental purposes without payment to meof any royalty thereon.

This invention relates to a method and means for reworking a pump of thegear or root type in which the bore has become scored or otherwisedamaged. It is particularly applicable where one or more liners of lessthan a complete circumference are to be securely attached to the innerperiphery of the bore.

Prior to this invention pumps of the above type,

the bore of which had become worn, scored, corroded or mutilated, or forany reason had too great clearance between the rotating part and thebore, were discarded, resulting in a great loss where a large number ofthe pumps are used.

It is therefore an object of this invention to provide a method ofprocedure and the necessary means t9 rework and reline the pumpcylinders bring them back to their original dimensions, to the end thatinterchangeability of the bores and rotating elements may be maintained.

Another object is to provide a method and means whereby asemicylindrical liner of somewhat more or less than a half circumferencemay be securely attached to the inner periphery of a rebored pump body,the liner being then rebored to standard dimensions.

Other objects and advantages will become evident as the invention isdescribed in detail and reference is had to the drawing, wherein Fig. lis a plan View of a gear pump body showing the bore as it appears beforeit is reworked.

Fig. 2 shows a plate jig for locating certain holes, the drilling ofwhich constitute the first step in my method.

Fig. 3 is a plan view of the pump body showing the holes which have beendrilledwith the aid of the jig, Fig. 2.

4 is an elevational view of a boringtool employed in performing thesecond, step of my method which changes the pump body from the conditionshown in Fig. 3 to the condition shown I in Fig. 5.

amended April 30, 192 8;370 o.

the liner keys. may be formed as an integral part 'of, the liner.

Fig. 10 is an axial section of the forming die taken at ill-l9 of Fig.9.

. Like reference characters refer to like parts throughout the severalviews.

Referring to Fig. 1, a pump body Ill is bored at [2 and Hi, the boredportion being respectively slightly over and slightly under asemi-circumference. A shaft IQ for rotating the drive gear of the. pumpand astud it upon which the idler gear may rotate, extend upwardconcentrically with thebore'd portions. Suction and discharge openingsfell and 22 extend axially through the the bored surfaces. k'ihe drilljig shown in Fig. 2 consists of a relascored or otherwise rendered unfitfor holding pressure between the ends of the gear teeth and it itivelythin plate 28 having two holes 36 and 32 ,whichare spaced the samedistance apart as the *shaft, ifiand stud H! in Fig. 1 and are slidablyfittedthereover. Holes 3% and 35 in the jig align with holes and 26 inthe body, whereby the jigmay be bolted to the body through these holes.The angles A and B between drill guide holes 38 of the jig are soselected that the centers of the ,1 drilled holes Gil shown in Fig. 3will be set back a reasonable distance C from the perimeters ofthesuction and discharge openings 2% and 22 and with the perimeters ofholes 38 of the jig a distance D, Fig. 3, from the perimeters of thebored .surfaces l2 and I 4. The dimension E, Fig. 3, rep- ,jresents .thedesired finished bore of the pump, -;and the dimensionD represents thefinished thickness of the liners which are to be secured to g thesurfaces ofthe bored portions l2 and i i. The

axial depth of the holes 40 should be equal to the axial {depth of thesebored portions. The liner which is to be insertedwill be enough thickerthan the dimension D to allow for a finish cut after the liner issecured in the pump body.

Fig. 4 shows a boring tool, 42 which is employed for-removing metalequal to the thickness D from the surfaces 12 and M. The tool comprisesa body; 44 and shank 46 with appropriate threaded portion 48 for holdingthe tool in the spindle of a machine. The bit 56 is held in an angularopen- ,,ing..by the set screw 52.

The bore 54 of the bit .shouldlfit slidably over the shaft [6 and stud[8 .of; the .pump body. and the radius F of the bit should equal thedimension D plus the radius E of Fig. 3. A threaded opening 56 may beprovided with a set screw (not shown) for setting the bit to the properradius F, but this set screw must be removed to permit the bore 54 topass over the shaft [6 and stud 8.

The tool 52 having been provided, the body l and the tool are secured inany appropriate machine which will impart relative rotation between thetool and the body, it being of course important that when the cut isbeing taken from the surface I2, the axis of the tool and that of theshaft id be coincident, and that when the cut is being taken from thesurface I4, the axis of the tool and that of the stud Ill be coincident.If these conditions prevail, it is unimportant whether it is the body Itor the tool 52 which revolves.

When the layer D has been removed from both the surface l2 and thesurface M, Fig. 3, and the wall between the bore and the small holesthus broken through and the sharp corners 58 which result where therebored surfaces 60 and 62 cut into the holes it have been removed thebody will appear as in Fig. 5 and be ready to have the liner 6 Fig. 6secured in place over the surface 62. A similar liner will be providedby means of a fixture differing from the fixture 68, Fig. 6, only inthat it will have the keys spaced to the angle B, Fig. 2, instead of tothe angle A.

In order to securely hold the liner in position against the surfaces 69and 6'3, the liners are provided with round keys 56, Fig. 6, the keysbeing silver soldered 01' similarly secured to the liners While they areheld in the locating fixture B8.

The liners 6 5, Fig. 6, may be formed from flat sheet stock bent tosemicylindrical shape, as shown, and held in the fixture 88 by a plug 18while the keys are soldered thereto, or they may consist of a length oftubing as at T2, the surplus portion of which may be cut off anddiscarded, or in the case of the surface 62, Fig. 5, where the angularmeasurement A is considerably less than 180 degrees, one length oftubing will provide two liners fi l. To facilitate soldering, thefixture 68, intermediate the ends, may be cut away as at Hi.

When the assembly of liner and keys is removed from the fixture 68, Fig.6, it will appear as in Fig. This assembly is now press fitted into apump body which has been prepared as in Fig. 5 to cover the surface 62and a like liner assembly with angular spacing B will be pressed intothe body over the surface Ell, whereupon the body will appear as in Fig.8. A light finish cut will now be taken off the surfaces It and '58,Fig. 8, with a tool similar to the tool 42, Fig. e, and the reworkedpump body will be complete.

To clarify the terminology herein, whenever the ends of the bore or ofthe liner are mentioned, it shall be taken to mean their termination inan axial direction, and when the edges of the bore or of the liner arementioned, it shall be taken to mean their termination in acircumferential direction.

As an alternative to soldering round keys 66 to the outer surfaces ofthe liners, keys 89, Fig. 9, may be formed integral with the liners byemploying a forming die 82. Die 82 consists of a die block 84 havingangularly spaced axially extending grooves for the keys 80 with formingpunches 8% for pressing the metal of the liner 83 into the grooves toform the keys 8!]. The

forming punches consist of blades 86 having their inner edges 90beveled, tapered plugs 94 being provided for forcing the bladesoutwardly to form the keys. The blades 86 are kept in position andguided in slots in a larger cylindrical plug 96 having an axial openingequal to the body of the small plugs 94.

Having described my method, I claim:

1. Steps in the method of securing a liner in a pump body having a boreof less than a full circumference which consists of drilling a series ofsmall axially parallel holes back from the edges of the bore and withtheir perimeters at a distance from the perimeter of the original pumpbore equal to the finished thickness of the liner, enlarging the pumpbore until the perimeter of the bore cuts through into the perimeters ofthe small holes, burring the sharp corners where the bore cuts throughinto the small holes, securing a series of round pins to the outersurface of the liner back from the edges of the liner with their axesparallel to the axis of the liner and angularly spaced a distance equalto the angular spacing of said small holes, pressing the liner axiallyinto the enlarged bore with the pins in said small holes, then boringthe liner to the diameter of the original pump bore.

2. Steps in the method of fastening an arcuate section of a cylindricalliner into an arcuate portion of a cylindrical bore which consists ofdrilling a pair of circumferentially spaced small holes back from theedges of said arcuate portion and positioned radially to leave a wallbetween the perimeter of the bore and the perimeters of the small holes,enlarging the bore until its perimeter extends into said small holes,burring the corners where the perimeter of the bore cuts the perimeterof the small holes, securing a pair of axially parallel keys to theexterior of the liner back from the edges thereof and circumferentiallyspaced to conform to the circumferential spacing of said small holes,pressing the liner and keys axially into the bore and small holesrespectively, then taking a light out from the inside surface of theliner.

3. Steps in the method of fastening an arcuate section of a cylindricalliner into an arcuate section of a cylindrical bore, the liner and boreeach comprising less than a full circumference, which consists ofdrilling a pair of axially parallel holes radially beyond the bore, oneback from each edge of the arcuate section of said bore, enlarging thebore until it joins said holes, providing rounded keys on said linerback from the edges of the arcuate section of the liner andangularly'spaced to correspond to said holes, and pressing said arcuateliner and its keys axially into said arcuate bore and said holes.

4. Steps-in the method of securing a liner which is in the form of anarcuate section of a cylinder with circuinferentially spaced axiallyparallel keys on the outside, one back from each edge of said section,to the inside of an arcuate section of a bore, which consists ofdrilling circumfercntially spaced axially parallel holes correspondingto said keys near but not touching the section of the bore, enlargingthe bore section until it merges with said holes, burring the corners atthe juncture of said bore section and said holes, then pressing saidliner and its keys axially into said bore section and its holes.

WESLEY .B. HOOK.

(References on following page) REFERENCES CITED The following referencesare of record in the tile of this patent:

UNITED STATES PATENTS Number Name Date Mossberg Nov. 29, 1892 Brigel May13, 1902 Number

